Vicarious Group Research Articles

Evolution of the Sabulina verna group (Caryophyllaceae) in Europe: A deep split, followed by secondary contacts, multiple allopolyploidization and colonization of challenging substrates

One of the major goals of contemporary evolutionary biology is to elucidate the relative roles of allopatric and ecological differentiation and polyploidy in speciation. In this study, we address the taxonomically intricate Sabulina verna group, which has a disjunct Arctic–alpine postglacial range in Europe and occupies a broad range of ecological niches, including substrates toxic to plants. Using genome-wide ddRAD sequencing combined with morphometric analyses based on extensive sampling of 111 natural populations, we aimed to disentangle internal evolutionary relationships and examine their correspondence with the pronounced edaphic and ploidy diversity within the group. We identified two spatially distinct groups of diploids: a widespread Arctic–alpine group and a spatially restricted yet diverse Balkan group. Most tetraploids exhibited a considerably admixed ancestry derived from both these groups, suggesting their allopolyploid origin. Four genetic clusters in congruence with geography and mostly supported by morphological traits were recognized in the diploid Arctic–alpine group. Tetraploids are split into two distinct and geographically vicariant groups, indicating their repeated polytopic origin. Furthermore, our results also revealed at least five-fold parallel colonization of toxic substrates (serpentine and metalliferous), altogether demonstrating a complex interaction between geography, challenging substrates and polyploidy in the evolution of the group. Finally, we propose a new taxonomic treatment of this complex.

Vicarious Group Trauma among British Jews

Given that literature on the intra- and inter-generational transmission of traumas is mainly based on secondary literature and focuses on the transmission of trauma memory in terms of the historical knowledge of group trauma, this article develops the theory of vicarious group trauma and tests this theory by exploring vicarious traumatization in the everyday lives of Jews in Britain through the methods of observation and in-depth interviewing. Vicarious group trauma is defined as a life or safety-threatening event or abuse that happened to some members of a social group but is felt by other members as their own experience because of their personal affiliation with the group. The article finds that the vicarious sensation of traumatic group experiences can create anxiety, elicit perceptions of threat and, by extension, hypervigilance among Jews. The findings demonstrate that group traumas of the past interpenetrate and interweave with members’ current lives and in this way can also become constitutive of their group identity. An institutional focus on threats to Jews can inform the construction and reinforcement of traumatization symptoms and accordingly vicarious group trauma. This article suggests an association between the level of involvement of group members in the collective’s social structure and the prominence of vicarious group trauma among them.

Escaping to the summits: Phylogeography and predicted range dynamics of Cerastium dinaricum, an endangered high mountain plant endemic to the western Balkan Peninsula

The Balkans are a major European biodiversity hotspot, however, almost nothing is known about processes of intraspecific diversification of the region’s high-altitude biota and their reaction to the predicted global warming. To fill this gap, genome size measurements, AFLP fingerprints, plastid and nuclear sequences were employed to explore the phylogeography of Cerastium dinaricum. Range size changes under future climatic conditions were predicted by niche-based modeling. Likely the most cold-adapted plant endemic to the Dinaric Mountains in the western Balkan Peninsula, the species has conservation priority in the European Union as its highly fragmented distribution range includes only few small populations. A deep phylogeographic split paralleled by divergent genome size separates the populations into two vicariant groups. Substructure is pronounced within the southeastern group, corresponding to the area’s higher geographic complexity. Cerastium dinaricum likely responded to past climatic oscillations with altitudinal range shifts, which, coupled with high topographic complexity of the region and warmer climate in the Holocene, sculptured its present fragmented distribution. Field observations revealed that the species is rarer than previously assumed and, as shown by modeling, severely endangered by global warming as viable habitat was predicted to be reduced by more than 70% by the year 2080.

Changing Routines: A Process Model of Vicarious Group Learning in Pharmaceutical R&D

Prior research has indicated that groups frequently change their routines drawing on the experience of others and that this has significant performance effects. But how group routine change occurs through this process of vicarious learning is not clear. Using a qualitative field study of drug development teams in one pharmaceutical firm, I examine how groups change routines drawing on the prior related experience of other groups. An inductive analysis suggests that this process does not follow the simple find-and-copy model often assumed in the literature and identifies four distinct subprocesses involved: identification, translation, adoption, and continuation. This process model adds to understanding of vicarious learning by showing that it is a more varied process than it is commonly construed to be and that not only experience- seeking groups, but also groups that are the source of the experience, play important and shifting roles throughout. Thus, this study contributes to theories about how groups change their routines by elucidating how they alter their routines through vicarious learning.

Phylogenetic relationships within the New World endemicZeltnera(Gentianaceae‐Chironiinae) inferred from molecular and karyological data

The New World endemic genus Zeltnera consists of 25 species mainly distributed in the western part of the United States and Mexico. Chromosome counts performed on 113 populations (24 species) reveal extensive congruence between chromosomal groups and the assemblages obtained from analyses of nuclear ribosomal DNA (ITS) and chloroplast DNA (trnL intron and trnL-F intergenic spacer) sequences. Karyological and molecular data sets support three main biogeographic groups for Zeltnera. A first and mainly unresolved cluster (n = 17 and n = 20) occurs in California, whereas two other clades are centered in the Texas region (n = 20 and n = 21) and in Mexico (n = 21 and n = 22). Under the assumption of a molecular clock, and using both dispersal and vicariance explanations for the current distribution of the respective species, the genus is thought to have a North American origin with considerable diversification in the early Pliocene (ca. 5 million years ago). Geological events, such as desert formation and mountain orogenies, have created insuperable barriers that today separate the three major and likely vicariant groups.

Several Pleistocene refugia detected in the high alpine plant Phyteuma globulariifolium sternb & hoppe (Campanulaceae) in the European Alps.

Phyteuma globulariifolium is a high alpine plant species growing in the European Alps and the Pyrenees. In order to elucidate its glacial history, 325 individuals from 69 populations were analysed using the amplified fragment length polymorphism (AFLP) technique. A strongly hierarchical phylogeographical pattern was detected: Two major east-west vicariant groups can be separated along a gap in the distributional area. A further subdivision into at least four populational groups is in congruence with presumed peripheral glacial refugia. There is no indication for survival on unglaciated mountain tops (nunataks) in the interior of the Pleistocene ice shield covering the Alps. Our results favour glacial survival in peripheral, unglaciated or not fully glaciated areas. Populations of P. globulariifolium in the Pyrenees are the result of relatively recent long-distance dispersal. Within the Alps, there is strong differentiation among groups of populations, whereas within them the differentiation is weak. This suggests high levels of gene-flow over short to middle distances.

Biodiversité intraspécifique dans les formations prairiales III—Vicariance chorologique et écologique dans l'est de la France et conclusions générales

Summary In this study, two vicarious groups from the North East of France are analysed. In the Lathyrus pratensis group, the oriental diploid cytotype is replaced along the valleys of the Moselle and Meuse by the tetraploid one which is a South Western plant. In the Southern part of this territory, in the Jura, the two cytotypes are sympatric and their distribution is then ecological, the tetraploids being in the hydrophytic part of the territory. In the Dactylis glomerata group, two taxas, one diploid (D. g. ssp. lobata) and one tetraploid (D. g. ssp. glomerata) are sympatrie in the North Eastern region where they are growing in different habitats, but they are able to hybridize, as morphological and biochemical proofs show.

FAUNAL RELATIONSHIPS BETWEEN EASTERN NORTH AMERICA AND EUROPE AS SHOWN BY INSECTS

AbstractThe supercontinent of Pangaea, which once included most lands, fragmented during the Mesozoic. By the Late Cretaceous there were two northern land masses that were strikingly different from those of present day: Asiamerica consisting of present western North America and Asia; and Euramerica comprising Europe and eastern North America. Mild climates facilitated the spread of terrestrial organisms within each of these land masses, but epicontinental seas hindered movements between Europe and Asia and between eastern and western North America.The insects of Euramerica presumably once formed a fauna extending from eastern North America to Europe that differed from the fauna of Asiamerica. The opening of the North Atlantic separated insects in Europe from those in eastern North America. This produced vicarious patterns, with some insects of eastern North America now being more closely related phylogenetically to those of Europe than to those of western North America. Most groups of insects have not been examined for such trans-Atlantic vicariances, but studies reviewed in this paper suggest such relationships for some groups of Collembola, Hemiptera, Homoptera, Coleoptera, Diptera, and Hymenoptera.The last suitable land connections between Europe and eastern North America were severed approximately 20–35 million years ago. The insects separated by this severance evolved at different rates. Some groups split in this way have apparently undergone little evolution and have the same species on both sides of the North Atlantic, but other vicarious groups have differentiated into taxa that are now distinct at specific and supra-specific levels.The opening of the North Atlantic probably split both tropical- and temperate-adapted insects in Euramerica. However, without fossil data it is difficult to identify the biogeographical patterns resulting from such splitting of the tropical-adapted groups. Most presently recognized European and eastern North American vicarious patterns of insects were probably caused by division of Euramerica rather than dispersal across Beringia.

Aspects of freshwater mollusc ecological biogeography

Freshwater molluscs include a variety of groups derived independently from marine ancestry, and varying in range of habitat, reproduction, and distribution. The fossil record shows the great age of most families, that likely differentiated in the Paleozoic. Present-day distributions of species and higher groups are rationalized as due to different ranges of habitat, life history, and means of dispersion, with a strong historical component. At the global level distribution of 42 principal families of freshwater and marginally marine molluscs is summarized. Most are widespread, the others representing only a few types of distributiion: groups characteristic of the southern continents, Tethyan, or localized. Localized families are mostly prosobranchs, and are concentrated in areas otherwise noted for endemism. The Atlantic and Indo-Pacific Oceans have vastly different relationss to the ranges of freshwater molluscs. The Atlantic cuts across genera and sets of genera, as if it came into being after the evolution of those groups. The Pacific is not so crossed, but bordered with primitive and local families, as if development of the Pacific basin were earlier and accompanied origin of living families of pulmonates. The fossil record in North America is reviewed briefly. Already in the Cretaceous a faunistic division is recognizable. Some groups in the west are related to those of east Asia, others in the east are of trans-Atlantic relationships. Withdrawal of the epeiric sea from the mid-continent exposed what can be viewed as an enormous land bridge linking different faunistic regions. These regions retain distinctiveness today: no large scale faunal migrations have occurred. Supposed migrations to South American and Australia are therefore dismissed. Freshwater mussels have often been employed in zoogeographic studies. The region west of the Rocky Mountains in North America has a sparse fauna of Asiatic affinities. Throughout all of Cenozoic time these features have been characteristic, emphasizing the hisorical value of mussel distribution. The historical roots of some zoogeographic thoughts are traced back to Charles Lyell, who introduced uniformitarianism in geology. The principle that the distribution of different groups of freshwater molluscs is carried out in different ways, determined by range of habitat and life history, is uniformitarian. It is based on the action of presently observable processes, and on their result over long periods of time. Attention to details of modern ranges, and recognition of polytypic and vicariant groups, is in full keeping with Lyell's urging “patiently to explore the realities of the present”. Lyell's belief in a center of origin of species captivated the mind of Charles Darwin. Believing in evolution, he nevertheless was compelled to deal with geographic distribution in a Lyellian, non-evolutionary way. Efforts to deal with animal geography by numbers of immigrants, flying birds, moving plates, and floating rafts go back beyond Darwin to Lyell's special creation. The uniformitarian interpretation of geographic distribution is linked causally to the uniformitarian approach of geology. Both are corollaries of a more general principle: earth and life evolve together. This also provides the premises for interpretations of the past.

Studies in observational paired-associate learning: Informational, social, and individual difference variables

Four experiments examined the relative importance of informational (proportion of correct responses and kinds of errors emitted by a model), social (model competency, sex of model, video vs. audio taped model), and individual difference (sex of subject, grade) variables in observational paired-associate learning. In Experiments I–III, vicarious subjects received cycles of study-model-test trials, while direct subjects were given the same sequences with intervening test or stimulus familiarization trials. In Experiment IV, vicarious subjects received cycles of study-test-model-test trials, while direct subjects received the cycles with a test trial replacing the model trial. No confirmation was provided on test and model trials. Whereas the effects attributable to social and individual difference variables were generally negligible, mere accuracy of the model's responses repeatedly covaried with performance on the last test trial of each cycle. Conditional analyses established that (1) vicarious facilitation is comparable across cycles and localized in items responded to incorrectly on immediately preceding test trials, and (2) observers learn fewer incorrect than correct model responses. Vicarious groups performed at reliably higher levels than direct subjects on model correct but not incorrect items. The results strongly suggest a close correspondence between direct and vicarious verbal learning principles and mechanisms.

Taxonomic studies in Avena abyssinica and A. vaviloviana, and some related species

This paper reports the use of micromorphologic attributes taken from the lodicules, epiblasts, and disarticulating scars for purposes of circumscription of the taxa associated with the names A. abyssinica and A. vaviloviana and their F1 hybrids, and also A. barbata. Furthermore it is shown that the epiblast can serve as a good marker to distinguish between the hexaploid A. byzantina and the tetraploid A. abyssinica, especially for those cases where previously only the chromosome number could have served this purpose. From the micromorphological findings, some cytological data, and plant distributional data, the author decided to regard A. abyssinica, A. barbata, and A. vaviloviana as separate species. The status of these species in previous classifications is compared with that proposed here. The many different classifications used in the past are attributed to the fact that no reliable diagnostic morphological markers were discovered by previous workers. A connection was discovered between A. occidentalis of the Canary Islands and the tetraploid abyssinian oats and a close relationship in this vicarious group is speculated.